Water Characteristic Curve and Shrinkage Characteristics of Different Sodification Degree

Abstract

【Objective】 The purpose of this paper is to explore the effect of different sodium on soil water holding capacity and shrinkage characteristics, 【Method】 The soil was saturated with pure water and NaCl solutions (TDS-3, TDS-10,TDS-20, TDS-30) with concentrations of 3, 10, 20 and 30 g/L respectively, and the soil water characteristic curve and soil shrinkage characteristic curve were measured. 【Result】 The results showed that, the degree of sodium had an effect on soil water characteristic curve, low sodium salt(TDS-3) compared with other high salinity treatment and blank treatment, reduced the proportion of ventilation, capillary and void, and enhanced the water holding capacity while high sodium salt treatment (TDS-10, TDS-20, TDS-30) weakened the water holding capacity. the effective linear shrinkage and suction of each treatment met the logarithmic relationship, and the soil shrinkage had a negative correlation with the volume water content; three linear regression analysis showed that the effective linear shrinkage and suction of each treatment met the logarithmic relationship, The model could be divided into three parts: abnormal shrinkage, structural skrinkage and pseudo shrinkage. 【Conclusion】 Sodium salt solution has an effect on the pore structure of soil, the relative number of each pore changes, the colloidal particles of soil are destroyed, and the difficulty of water retention and soil shrinkage characteristics change.

Keywords

• swcc
• soil shrinkage characteristic curve
• capillary porosity